I wouldn't play with the horn. The temptation to breathe deep is great. I would buzz on the mouthpiece with short breaths as much as you feel comfortable with. Buzzing requires less air, but is still good work for the embouchure. That way when you infection is gone, you won't be totally dead.

If you do decide to keep playing or buzzing, make sure to sanitize your horn/mouthpiece. The same bacteria that caused your illness loves to live in warm damp places and you don't want to chance a reinfection once you get well.

By the way, make sure you take your whole regimen of antibiotics, even if you feel better before they run out.